In a competitive sale, a broker dealer will place a sealed bid on bonds at the designated time and date as determined by the official notice of sale. The terms and structure of the issuance as well as the restrictions are presented prior to the sale. Most often, the bid will be for the entirety of the issue, with partial bids not allowed.
The bidding broker dealer along with their syndicate group (other broker dealers) are able to take indications of interest on a transaction prior to the time of sale, or simply market them to investors after purchasing the issuance.
Typically, the bonds are awarded to the bidder offering the lowest interest cost to the issuer.